The 5 year bond (N517100F) will go on sale in March, 2017. There's a 10 year bond (NZ07100S) available for sale next month (February, 2017).
You're much better off with a 5 or 10 year bond instead of a 60 month or 120 month Fixed Deposit. Yes, every SRS custodian allows buying original issue SGSs (what I'm recommending instead of Fixed Deposits), and most if not all allow buying/selling SGSs on the secondary market (not what I recommend, but probably still better than FDs).
Singapore Government Securities are backed by the full faith and credit of the AAA-rated Singapore government, no matter how much of them you hold. (There is no $50K SDIC limit.) It's the safest possible asset you can hold in a SRS, and it happens to offer better yields than a bank FD.
May I ask you how to buy new SGS bonds using SRS? I checked DBS site only cash is allowed (No mention of SRS/CPF), see https://www.dbs.com.sg/personal/ibanking/faq/sgsbond.page
The only way is buy from brokers like Kayhian or DBS Vickers and pay fees and commissions?

